Here's Shazaam's post
http://www.ducatisportingclub.com/sh...ghlight=Airbox in it Larry mentions 130% of the capacity. so for a 620 thats 803cc so less than a litre between the butterflies and the air filter, for my 1000SS it woule be a figure of 1300cc so as they run the same airbox I doubt if my Class A bike is finding it a restriction